Thermostat housing question

How the hell do I get this thing back on.. it was pretty tight coming out, but now it won't full seat properly like it did before..

no, I didn't remove my entire throttle body assembly just to replace a damn thermostat.. anyone got any idea's?

starting to get really frustrated with the proprietary sink and seal effects that oldsmobiles seem to be notorious for.. I just wish I could put a gasket on,, and 2 bolts and that be it.... but no,, olds came out with a sound idea, and put it in a bad spot.. under the throttle body housing..

I swear I will not tear apart my fuel system and throttle system just to get a damned thermostat in..

gonna wait a little before I go back out in this heat...

Chris